Greuel also had a subpoena prepared for Verizon, but the company surrendered initial information, she said.

The investigation was connected to an audit released by Greuel in May 2011 that found the city wasted an estimated $1 million on cell phone costs for public employees.

Greuel told KNX 1070 NEWSRADIO she has tried unsuccessfully to acquire basic user data from the city’s cell phone carriers to better determine what expenditures are being made.

“The city of Los Angeles is a client, is someone that deserves that information, and you’ll see that today we’re issuing those subpoenas to ensure that we are getting our best bang for our buck,” Greuel said.

Greuel had previously reviewed seven city departments with contracts for over 11,800 cell phones and found the Department of Water & Power had the most number of city-issued phones at 3,971, followed by the Los Angeles Police Department at 1,525, L.A. World Airports (872), the L.A. Fire Department (798), the General Services Department (580), and the Department of Building and Safety (494).

She said the city could save up to $1 million by simply improving management of existing contracts with phone carriers – if they would only cooperate.

“It is absurd that companies doing business with the City of Los Angeles want to deny access to the City’s cell phone bills,” Greuel said. “I urge AT&T, T-Mobile and Sprint to hand over the city’s bills and stop acting as though they have something to hide.”